Table 2.
Hazard ratios (HRs) and 95% confidence intervals (CIs) of mortality after gastric adenocarcinoma diagnosis in relation to metformin use among diabetes patients.
| Disease-specific mortality | All-cause mortality | |||||
|---|---|---|---|---|---|---|
| Number of deaths | Crude HR (95% CI) | Adjusted HR (95% CI)a | Number of deaths | Crude HR (95% CI) | Adjusted HR (95% CI)a | |
| All participants | ||||||
| No metformin | 242 | 1.00 (Reference) | 1.00 (Reference) | 330 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 451 | 0.69 (0.59–0.81) | 0.79 (0.67–0.93) | 632 | 0.70 (0.61–0.80) | 0.78 (0.68–0.90) |
| Men | ||||||
| No metformin | 155 | 1.00 (Reference) | 1.00 (Reference) | 220 | 1.00 (Reference) | 1.00(Reference) |
| Metformin | 312 | 0.75 (0.62–0.92) | 0.85 (0.69–1.03) | 460 | 0.77 (0.66– 0.91) | 0.84 (0.71–0.99) |
| Women | ||||||
| No metformin | 87 | 1.00(Reference) | 1.00 (Reference) | 110 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 139 | 0.59 (0.45–0.77) | 0.66 (0.49–0.89) | 172 | 0.57 (0.45–0.72) | 0.62 (0.48–0.81) |
| Age < 73 years | ||||||
| No metformin | 80 | 1.00 (Reference) | 1.00 (Reference) | 116 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 218 | 0.78 (0.60–1.00) | 0.83 (0.64–1.09) | 316 | 0.76 (0.62–0.95) | 0.80 (0.64–1.00) |
| Age ≥ 73 years | ||||||
| No metformin | 162 | 1.00 (Reference) | 1.00 (Reference) | 214 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 233 | 0.71 (0.58–0.87) | 0.80 (0.64–0.99) | 316 | 0.72 (0.61–0.86) | 0.83 (0.69–0.99) |
| Gastric cardia adenocarcinoma | ||||||
| No metformin | 58 | 1.00 (Reference) | 1.00 (Reference) | 108 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 127 | 0.70 (0.51–0.96) | 0.82 (0.60–1.14) | 236 | 0.67 (0.53–0.84) | 0.75 (0.59–0.95) |
| Gastric non-cardia adenocarcinoma | ||||||
| No metformin | 185 | 1.00 (Reference) | 1.00 (Reference) | 223 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 324 | 0.71 (0.59–0.85) | 0.79 (0.65–0.95) | 396 | 0.72 (0.61–0.85) | 0.80 (0.67–0.95) |
| Tumour stage Tis-II | ||||||
| No metformin | 37 | 1.00 (Reference) | 1.00 (Reference) | 59 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 78 | 0.73 (0.49–1.08) | 0.87 (0.57–1.31) | 131 | 0.76 (0.56–1.04) | 0.89 (0.64–1.23) |
| Tumour stage III–IV | ||||||
| No metformin | 141 | 1.00 (Reference) | 1.00 (Reference) | 181 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 303 | 0.66 (0.54– 0.80) | 0.71 (0.58–0.88) | 400 | 0.66 (0.55–0.79) | 0.71 (0.59–0.85) |
| Charlson Comorbidity Index 0 | ||||||
| No metformin | 116 | 1.00 (Reference) | 1.00 (Reference) | 155 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 275 | 0.66 (0.53–0.82) | 0.71 (0.57–0.89) | 387 | 0.68 (0.57–0.82) | 0.70 (0.58–0.85) |
| Charlson Comorbidity Index 1 | ||||||
| No metformin | 62 | 1.00 (Reference) | 1.00 (Reference) | 85 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 109 | 0.82 (0.60–1.12) | 0.91 (0.66–1.27) | 155 | 0.84 (0.64–1.09) | 0.90 (0.68–1.19) |
| Charlson Comorbidity Index ≥ 2 | ||||||
| No metformin | 64 | 1.00 (Reference) | 1.00 (Reference) | 90 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 67 | 0.78 (0.56–1.11) | 0.85 (0.59–1.22) | 90 | 0.74 (0.55–0.99) | 0.81 (0.59–1.11) |
| No gastrectomy | ||||||
| No metformin | 202 | 1.00 (Reference) | 1.00 (Reference) | 271 | 1.00 (Reference) | 1.00 (Reference) |
| Metformin | 347 | 0.71 (0.60–0.84) | 0.82 (0.68–0.99) | 494 | 0.73 (0.63–0.85) | 0.81 (0.69–0.95) |
| Gastrectomyb | ||||||
| No metformin | 40 | 1.00 (Reference) | 1.00 (Reference) | 59 | 1.0 (Reference) | 1.00 (Reference) |
| Metformin | 104 | 0.81 (0.56–1.16) | 0.87 (0.60–1.27) | 138 | 0.73 (0.54–0.99) | 0.79 (0.58–1.08) |
aAdjusted for sex, age, calendar year of gastric adenocarcinoma diagnosis, use of non-steroidal anti-inflammatory drugs or aspirin, use of statins, and Charlson Comorbidity Index.
bPatients who underwent gastrectomy were followed up from the date of surgery.